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During mammalian fertilization, repetitive intracellular Ca2+ increases known as Ca2+ oscillations occur. These oscillations are considered crucial for successful fertilization and subsequent embryonic development. Numerous researchers have endeavored to elucidate the factors responsible for inducing Ca2+ oscillations across various mammalian species. Notably, sperm-specific phospholipase C zeta (PLCζ) emerged as a prominent candidate capable of initiating Ca2+ oscillations, particularly in mammals. Genetic mutation of PLCζ in humans results in the absence of Ca2+ oscillations in mouse oocytes. Recent studies further underscored PLCζ's significance, revealing that sperm from PLCζ-deficient (Plcz1−/−) mice fail to induce Ca2+ oscillations upon intracytoplasmic sperm injection (ICSI). Despite these findings, observations from in vitro fertilization (IVF) experiments using Plcz1−/− sperm revealed some residual intracellular Ca2+ increases and successful oocyte activation, hinting at potential alternative mechanisms. In this review, we introduced the current hypothesis surrounding oocyte activation in mammals, informed by contemporary literature, and probed into the enigmatic mechanisms underlying mammalian fertilization-induced oocyte activation. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are present in a wide range of plants, animals, and microorganisms. Since AMPs are characterized by their effectiveness against emergent antibiotic-resistant bacteria, they are attracting attention as next-generation antimicrobial compounds that could solve the problem of drug-resistant bacteria. Persulcatusin (IP), an antibacterial peptide derived from the hard tick Ixodes persulcatus, shows high antibacterial activity against various Gram- positive bacteria as well as multidrug-resistant bacteria. However, reports on the antibacterial action and resistance mechanisms of IP are scarce. In this study, we spontaneously generated mutants showing increased a minimum inhibitory concentration (MIC) of IP and analyzed their cross-resistance to other AMPs and antibiotics. We also used fluorescent probes to investigate the target of IP activity by evaluating IP-induced damage to the bacterial cytoplasmic membrane. Our findings suggest that the antimicrobial activity of IP on bacterial cytoplasmic membranes occurs via a mechanism of action different from that of known AMPs. Furthermore, we screened for mutants with high susceptibility to IP using a transposon mutant library and identified 16 genes involved in IP resistance. Our results indicate that IP, like other AMPs, depolarizes the bacterial cytoplasmic membrane, but it may also alter membrane structure and inhibit cell-wall synthesis. [ABSTRACT FROM AUTHOR]

During mammalian fertilization, repetitive rises of intracellular calcium called calcium oscillations are required for full activation of oocytes. Therefore, oocytes such as round spermatid injected or somatic cell nuclear transferred require additional artificial activation which mimics the calcium oscillations. It is well recognized that sperm specific phospholipase C (PLCζ) is a strong candidate as the sperm factor which can induce calcium oscillations and, at least in mammals, the genetic mutation of PLCζ in human causes male infertility due to the lack of calcium oscillations in the oocytes. Recent studies showed that the sperm lacking PLCζ (Plcz1−/−) still could induce rise(s) of intracellular calcium in the oocytes after IVF but not intracytoplasmic sperm injection (ICSI). In the ICSI oocytes, no pronuclear formation or development to the two-cell stage was observed. However, it is still unclear whether additional activation treatment can rescue the low developmental ability of Plcz1−/−-sperm-derived oocytes after ICSI. In this study, we examined whether oocytes injected with a Plcz1−/− sperm can develop to term by additional artificial activation. In oocytes injected a Plcz1−/− sperm and Plcz1−/− and eCS (another candidate of the sperm factor) double knockout sperm (Plcz1−/−eCS−/−), the rates of pronuclear formation were very low (2.0 ± 2.3% and 6.1 ± 3.7%, respectively) compared to control (92.1 ± 2.6%). However, these rates were dramatically improved by additional procedures of PLCζ-mRNA injection or SrCl2 treatment (Plcz1−/− sperm + PLCζ mRNA, Plcz1−/− sperm + SrCl2 and Plcz1−/−eCS−/− sperm + PLCζ mRNA; 64.2 ± 10.8%, 89.2 ± 2.4% and 72.6 ± 5.4%, respectively). Most of the oocytes were developed to the two-cell stage. After embryo transfer, healthy pups were obtained in all these groups (Plcz1−/− sperm + PLCζ mRNA:10.0 ± 2.8%, Plcz1−/− sperm + SrCl2:4.0 ± 4.3% and Plcz1−/−eCS−/− sperm + PLCζ mRNA: 10.0 ± 5.7%). The rate in Plcz1−/− sperm + SrCl2 group was significantly lower than that in control (26.0 ± 2.4%). Taken together, our present results show that additional activation treatment such as SrCl2 and PLCζ mRNA can fully support to develop to term even in oocyte injected Plcz1−/− sperm. In addition, PLCζ-induced oocyte activation is more suitable for successful development to term compared to that such as phenomenon induced by SrCl2. These findings will contribute to improvement for male-dependent human infertility and reproductive technologies in other mammalian species. [ABSTRACT FROM AUTHOR]

The delivery of curcumin (CUR) using the solid dispersion system (CUR solid dispersions; C-SDs) has been shown to improve CUR bioavailability. However, it is unclear how different particle sizes of C-SDs affect the bioavailability and biological activities of CUR. Hence, we prepared C-SDs in different sizes using food-grade excipients and evaluated their bioavailability and biological activities. By pulverizing large particle sizes of C-SDs using zirconia beads, we successfully prepared C-SDs I-IV (particle size: (I) 120, (II) 447, (III) 987, (IV) 1910 nm). When administrated orally in rats, the bioavailability of CUR was increased with decreasing C-SDs size, most likely by improving its solubility in micelles. When administrated intravenously in rats, blood concentrations of CUR were increased with increasing particle size, suggesting that larger C-SDs presumably control the metabolic conversion of CUR. In RAW264 cells, more CUR was taken up by cells as their sizes reduced, and the more potent their anti-inflammatory activities were, suggesting that smaller C-SDs were taken up through a number of cellular uptake pathways. Altogether, the present study showed an evident effect of C-SDs size on their bioavailability and anti-inflammatory activities—information that serves as a basis for improving the functionality of CUR. [ABSTRACT FROM AUTHOR]

Hydrogen can be stored in the interstitial sites of the lattices of intermetallic compounds. To date, intermetallic compound LaNi5 or related LaNi5-based alloys are known to be practical hydrogen storage materials owing to their higher volumetric hydrogen densities, making them a compact hydrogen storage method and allowing stable reversible hydrogen absorption and desorption reactions to take place at room temperature below 1.0 MPa. By contrast, gravimetric hydrogen density is required for key improvements (e.g., gravimetric hydrogen density of LaNi5: 1.38 mass%). Although hydrogen storage materials have typically been evaluated for their hydrogen storage properties below 10 MPa, reactions between hydrogen and materials can be facilitated above 1 GPa because the chemical potential of hydrogen dramatically increases at a higher pressure. This indicates that high-pressure experiments above 1 GPa could clarify the latent hydrogen absorption reactions below 10 MPa and potentially explore new hydride phases. In this study, we investigated the hydrogen absorption reaction of LaNi5 above 1 GPa at room temperature to understand their potential hydrogen storage capacities. The high-pressure experiments on LaNi5 with and without an internal hydrogen source (BH3NH3) were performed using a multi-anvil-type high-pressure apparatus, and the reactions were observed using in situ synchrotron radiation X-ray diffraction with an energy dispersive method. The results showed that 2.07 mass% hydrogen was absorbed by LaNi5 at 6 GPa. Considering the unit cell volume expansion, the estimated hydrogen storage capacity could be 1.5 times higher than that obtained from hydrogen absorption reaction below 1.0 MPa at 303 K. Thus, 33% of the available interstitial sites in LaNi5 remained unoccupied by hydrogen atoms under conventional conditions. Although the hydrogen-absorbed LaNi5Hx (x < 9) was maintained below 573 K at 10 GPa, LaNi5Hx began decomposing into NiH, and the formation of a new phase was observed at 873 K and 10 GPa. The new phase was indexed to a hexagonal or trigonal unit cell with a ≈ 4.44 Å and c ≈ 8.44 Å. Further, the newly-formed phase was speculated to be a new hydride phase because the Bragg peak positions and unit cell parameters were inconsistent with those reported for the La-Ni intermetallic compounds and La-Ni hydride phases. [ABSTRACT FROM AUTHOR]

Digalactosyldiacylglycerol- (DGDG-) monoestolide is a characteristic glycolipid in oats. DGDG-monoestolides possess a unique structure whereby a fatty acid of DGDG is replaced by a fatty acid ester of hydroxy fatty acid (FAHFA). While the physiological effects of DGDG and FAHFA have been reported previously, the effects of DGDG-monoestolides are unknown. Hence, we isolated a major DGDG-monoestolide molecular species from oats, analyzed its structure, and evaluated its anti-inflammatory effect. Based on GC-MS, MS/MS, and NMR analyses, the isolated compound was identified as a DGDG-monoestolide that contains the linoleic acid ester of 15-hydroxy linoleic acid (LAHLA) and linoleic acid (i.e., DGDG-LAHLA). The isolated DGDG-LAHLA was evaluated for its anti-inflammatory effect on LPS-stimulated RAW264 cells. The production of nitric oxide and cytokines (IL-6, TNF-α, and IL-10) were significantly decreased by DGDG-LAHLA, suggesting the anti-inflammatory effect of DGDG-LAHLA for the first time. In addition, our data showed a pronounced uptake of DGDG-LAHLA by cells. Some compounds corresponding to the predicted DGDG-LAHLA metabolites were also detected, suggesting that both intact DGDG-LAHLA and its metabolites may contribute to the above anti-inflammatory activities. These results are expected to expand the availability of oats as a functional food. [ABSTRACT FROM AUTHOR]

Despite the importance of the insight about the oxidation mechanisms (i.e., radical and singlet oxygen (1O2) oxidation) in extra virgin olive oil (EVOO), the elucidation has been difficult due to its various triacylglycerol molecular species and complex matrix. This study tried to evaluate the mechanisms responsible for EVOO oxidation in our daily use by quantitative determination of triacylglycerol hydroperoxide (TGOOH) isomers using LC-MS/MS. The standards of dioleoyl-(hydroperoxy octadecadienoyl)-triacylglycerol and dioleoyl-(hydroperoxy octadecamonoenoyl)-triacylglycerol, which are the predominant TGOOHs contained in EVOO, were prepared. Subsequently, fresh, thermal-, and photo-oxidized EVOO were analyzed. The obtained results mostly agreed with the previously reported characteristics of the radical and 1O2 oxidation of linoleic acid and oleic acid. This suggests that the methods described in this paper should be valuable in understanding how different factors that determine the quality of EVOO (e.g., olive species, cultivation area, cultivation timing, and extraction methods) contribute to its oxidative stability. [ABSTRACT FROM AUTHOR]

Basophils are the rarest granulocytes and have long been overlooked in immunological research due to their rarity and similarities with tissue-resident mast cells. In the last two decades, non-redundant functions of basophils have been clarified or implicated in a broad spectrum of immune responses, particularly by virtue of the development of novel analytical tools for basophils. Basophils infiltrate inflamed tissues of patients with various disorders, even though they circulate in the bloodstream under homeostatic conditions. Depletion of basophils results in the amelioration or exaggeration of inflammation, depending on models of disease, indicating basophils can play either beneficial or deleterious roles in a context-dependent manner. In this review, we summarize the recent findings of basophil pathophysiology under various conditions in mice and humans, including allergy, autoimmunity, tumors, tissue repair, fibrosis, and COVID-19. Further mechanistic studies on basophil biology could lead to the identification of novel biomarkers or therapeutic targets in a broad range of diseases. [ABSTRACT FROM AUTHOR]

Previous studies suggest that squalene (SQ) in sebum is oxidized by a photooxidation mechanism (i.e., singlet oxygen oxidation) to create SQ hydroperoxide (SQOOH), a compound that causes adverse skin conditions. However, oxidation of other lipids in sebum, such as linoleic acid (LA), has not been fully understood. Elucidating their oxidation, especially its mechanisms, may lead to a further understanding of the relationship between sebum oxidation and skin conditions. In this study, using HPLC–MS/MS, we aimed to detect LA hydroperoxide (LAOOH) directly from sebum and identify the oxidation mechanism of LA in sebum through analysis of LAOOH isomers. We developed extraction and HPLC–MS/MS analysis conditions that can sufficiently quantify each LAOOH isomer in sebum. Using this method, LAOOH was detected in samples from healthy individuals, demonstrating the presence of LAOOH in human sebum. Moreover, isomer analysis of LAOOH and SQOOH indicated that LA and SQ are oxidized in sebum by discrete oxidation mechanisms (LA oxidized by free radical oxidation, whereas SQ oxidized by singlet oxygen oxidation). Such results may further lead to the development of mechanism‐specific ways to prevent oxidation of sebum via a selection of appropriate antioxidants, ultimately leading to the promotion of skin health. [ABSTRACT FROM AUTHOR]

Purpose: Although giant oocytes (GOs) having about twice cytoplasmic volume compared with general oocytes in mammals including the human are rarely recovered, it is thought that GOs have potentially chromosomal abnormalities. The aim of the present study was to assess chromosome numbers in chromosome‐spindle complexes (CSCs) and polar bodies of human GOs by using micromanipulation for sampling and next‐generation sequencing (NGS) for analyses of the chromosome numbers. Methods: When recovered oocytes whose cytoplasm has lager than 140 µm or above, the oocytes were defined as GOs, and recovered GOs were vitrified. After warming, the CSCs, polar bodies, and enucleated cytoplasm were collected by micromanipulation from 3 GOs. The collected samples were analyzed by NGS. Results: Chromosomal aneuploidy in the GOs was confirmed in all the three GOs. Comparing the CSCs with the chromosomes from polar bodies, the deletion and overlapping chromosome numbers were complementary in each GO. Conclusions: The authors could collect the CSCs and the polar bodies from human GOs by micromanipulation, and then could analyze the chromosome numbers of the GOs by NGS method. As our data suggest that human GOs have chromosomal abnormalities, GOs should be excluded from clinical purpose as gamete sources for embryo transfer in the human. [ABSTRACT FROM AUTHOR]

The vitrification of immature germinal vesicle (GV) oocytes is an important way to preserve genetic resources and female fertility. However, it is well known that cryopreserved GV oocytes have very poor developmental ability and that further improvement in this technique is needed. We previously reported the successful vitrification of matured mouse oocytes with enclosed cumulus cells using the calcium-free vitrification solution supplemented with ethylene glycol (EG) by the minimal volume cooling (MVC) method. In this study, we investigated whether our method is applicable to the vitrification of mouse oocytes at the GV stage (GV oocytes). Following maturation and fertilization in vitro, vitrified GV oocytes showed high survival (94.3 ± 2.0%) and maturation (94.3 ± 2.1%) rates. Although the fertilization and blastocyst rates of vitrified oocytes (fertilization: 46.6 ± 4.9% and blastocyst: 46.6 ± 3.0%) were significantly lower than those of fresh oocytes (fertilization: 73.0 ± 7.1% and blastocyst: 71.6 ± 8.0%) (P < 0.01), there were no differences in the ability to develop to term between fresh oocytes (50.0 ± 8.4%) and vitrified oocytes (37.5 ± 4.6%) (P > 0.05). In conclusion, we here show, for the first time, the efficient production of live mice derived from vitrified GV oocytes. [ABSTRACT FROM AUTHOR]

Skin lesions, cataracts, and congenital anomalies have been frequently associated with inherited deficiencies in enzymes that synthesize cholesterol. Lanosterol synthase (LSS) converts (S)-2,3-epoxysqualene to lanosterol in the cholesterol biosynthesis pathway. Biallelic mutations in LSS have been reported in families with congenital cataracts and, very recently, have been reported in cases of hypotrichosis. However, it remains to be clarified whether these phenotypes are caused by LSS enzymatic deficiencies in each tissue, and disruption of LSS enzymatic activity in vivo has not yet been validated. We identified two patients with novel biallelic LSS mutations who exhibited congenital hypotrichosis and midline anomalies but did not have cataracts. We showed that the blockade of the LSS enzyme reaction occurred in the patients by measuring the (S)-2,3-epoxysqualene/lanosterol ratio in the forehead sebum, which would be a good biomarker for the diagnosis of LSS deficiency. Epidermis-specific Lss knockout mice showed neonatal lethality due to dehydration, indicating that LSS could be involved in skin barrier integrity. Tamoxifen-induced knockout of Lss in the epidermis caused hypotrichosis in adult mice. Lens-specific Lss knockout mice had cataracts. These results confirmed that LSS deficiency causes hypotrichosis and cataracts due to loss-of-function mutations in LSS in each tissue. These mouse models will lead to the elucidation of the pathophysiological mechanisms associated with disrupted LSS and to the development of therapeutic treatments for LSS deficiency. Author summary: Skin lesions, cataracts, and congenital anomalies have been frequently associated with inherited deficiencies of cholesterol synthetic enzymes. LSS encodes lanosterol synthase, an enzyme in the cholesterol biosynthesis pathway, and biallelic mutations in LSS have been reported in families with congenital cataracts and hypotrichosis. However, it remains to be clarified whether these phenotypes are caused by LSS enzymatic deficiency in each tissue, and disruption of LSS enzymatic activity in vivo has not yet been validated. We showed that LSS metabolic inhibition in patients with biallelic LSS mutations and congenital hypotrichosis in vivo by measuring metabolites of the LSS enzyme in the forehead sebum, which would be good biomarkers for the diagnosis of LSS deficiency. We recapitulated hypotrichosis and cataracts by creating tissue-specific Lss knockout mice. Our mouse studies confirmed that LSS deficiency causes hypotrichosis and cataracts due to loss-of-function mutations in LSS in each tissue. These mice will lead to the elucidation of the pathophysiological mechanisms associated with disrupted LSS and to the development of therapeutic treatments for LSS deficiency. [ABSTRACT FROM AUTHOR]

Squalene is a terpenoid found in human skin surface lipids (SSLs) and foods that possesses beneficial properties. However, since oxidation of squalene causes various complications, it is necessary to identify the mechanisms by which squalene is oxidized. In this study, we aimed to determine the oxidation mechanisms of squalene in SSLs and shark liver oil (SLO) supplements by the analysis of squalene monohydroperoxide (SQOOH) isomers, on the basis of our previous finding that different oxidation mechanisms yield different SQOOH isomers. Liquid chromatography–tandem mass spectrometry analysis of SQOOH isomers revealed that squalene in human SSLs was oxidized by singlet oxygen oxidation, whereas squalene in SLO was oxidized mainly by free radicals. As a result, we have presented the first evidence suggesting that the analysis of SQOOH isomers enables estimation of oxidation mechanisms. Estimating oxidation mechanisms by analyzing SQOOH isomers may provide a foundation for the prevention of skin diseases and food deterioration via regulation of squalene oxidation. [ABSTRACT FROM AUTHOR]

Background: Human infertility has become a serious and social issue all over the world, especially in developed countries. Numerous types of assisted reproductive technology have been developed and are widely used to treat infertility. However, pregnancy outcomes require further improvement. It is essential to understand the cross‐talk between the uterus (mother) and the embryo (fetus) in pregnancy, which is a very complicated event. Methods: The mammalian uterus requires many physiological and morphological changes for pregnancy‐associated events, including implantation, decidualization, placentation, and parturition, to occur. Here is discussed recent advances in the knowledge of the molecular mechanisms underlying these reproductive events — in particular, embryonic implantation and decidualization — based on original and review articles. Main findings (Results): In mice, embryonic implantation and decidualization are regulated by two steroid hormones: estrogen and progesterone. Along with these hormones, cytokines, cell‐cycle regulators, growth factors, and transcription factors have essential roles in implantation and decidualization in mice. Conclusion: Recent studies using the gene manipulation of mice have given considerable insight into the molecular mechanisms underlying embryonic implantation and decidualization. However, as most of the findings are based on mice, comparative research using different mammalian species will be useful for a better understanding of the species‐dependent differences that are associated with reproductive events, including embryonic implantation. Estrogen and progesterone (P4) orchestrate implantation window in mice. In mice, uterine sensitivity for accepting the embryo is composed from perceptive (Day 1‐3; with the day of vaginal plug observed being defined as Day 1), receptive (Day 4) and refractory (Day 5 afternoon). On Day 4, an increase of estrogen level is observed prior to the receptive stage (Top). Morphological changes of uterus from Day1 to Day 8 during pregnancy in mice (Bottom). [ABSTRACT FROM AUTHOR]

1-Deoxynojirimycin (DNJ) is a potent α-glucosidase inhibitor and thus beneficial for prevention of diabetes. While we have succeeded in obtaining the culture supernatant extract (CSE) rich in DNJ from microorganism source, information regarding its anti-hyperglycemic effect and safety were still limited. Therefore, this study was aimed to evaluate the anti-hyperglycemic effect and safety of microorganism DNJ. Oral sucrose tolerance test was performed, and the result showed that CSE was able to significantly suppress the blood glucose elevation and suggested DNJ as the main active compound. To determine its safety, the absorption and excretion of microorganism DNJ were evaluated using 15N labeling method. Our findings investigated the recovery rate of 15N from DNJ reached 80% up to 48 hours after oral administration, suggesting its rapid excretion, suggesting the safety of DNJ. This study verified the functional properties and safety of DNJ from microorganisms, suggesting its potential use for functional purpose. [ABSTRACT FROM AUTHOR]

Abstract: A detailed kinetic study was performed for the reaction of the aroxyl radical (ArO•) with eight vegetable oils 1–8, which contain different concentrations of α‐, β‐, γ‐, and δ‐tocopherols and ‐tocotrienols (‐Tocs and ‐Toc‐3s). The second‐order rate constants (ks) and aroxyl radical absorption capacity (ARAC) values for the reaction of ArO• with vegetable oils 1–8 (rice bran 1, perilla 2, rapeseed 3, safflower 4, grape seed 5, sesame 6, extra virgin olive 7, and olive oils 8) were measured in ethanol/chloroform/D2O (50:50:1, v/v/v) solution at 25 °C using stopped‐flow spectrophotometry. The ks value (16.1 × 10−3 L g−1 s−1) of rice bran oil 1 with the highest activity was 8.0 times larger than that (2.02 × 10−3) of olive oil 8 with the lowest activity. The concentrations (in mg 100 g−1) of α‐, β‐, γ‐, and δ‐Tocs and ‐Toc‐3s contained in the vegetable oils 1–8 were determined using high performance liquid chromatography‐mass spectrometry/mass spectrometry (HPLC‐MS/MS). From these results, it was clarified that the ArO•‐scavenging rates (ks) (i.e., the relative ARAC value) obtained for the vegetable oils 1–8 may be well explained as the sum of the product ∑ k s AOH ‐ i AOH ‐ i / 10 5 of the rate constant ( k s AOH ‐ i) and the concentration ([AOH‐i]/105) of AOH‐i (Tocs and Toc‐3s) included in vegetable oils. The results suggest that the ARAC assay method might be used in the evaluation of antioxidant activity of general food extracts. [ABSTRACT FROM AUTHOR]